Description and Brand Names

US Brand Name

Iodotope

Descriptions

Radiopharmaceuticals are agents used to diagnose certain medical problems or treat certain diseases. They may be given to the patient in several different ways. For example, they may be given by mouth, given by injection, or placed into the eye or into the bladder.

Radiopharmaceuticals are radioactive agents. However, when small amounts are used, the radiation your body receives from them is very low and is considered safe. When larger amounts of these agents are given to treat disease, there may be different effects on the body.

When radiopharmaceuticals are used to help diagnose medical problems, only small amounts are given to the patient. The radiopharmaceutical then passes through, or is taken up by, an organ of the body (which organ depends on what radiopharmaceutical is used and how it has been given). Then the radioactivity is detected, and pictures are produced, by special imaging equipment. These pictures allow the nuclear medicine doctor to study how the organ is working and to detect cancer or tumors that may be present in the organ.

Some radiopharmaceuticals are used in larger amounts to treat certain kinds of cancer and other diseases. In those cases, the radioactive agent is taken up in the cancerous area and destroys the affected tissue. The information that follows applies only to radiopharmaceuticals when used in small amounts to diagnose medical problems.

The dosages of radiopharmaceuticals that are used to diagnose medical problems will be different for different patients and depend on the type of test. The amount of radioactivity of a radiopharmaceutical is expressed in units called becquerels or curies. Radiopharmaceutical dosages given may be as small as 0.185 megabecquerels (5 microcuries) or as high as 1295 megabecquerels (35 millicuries). The radiation received from these dosages may be about the same as, or even less than, the radiation received from an x-ray study of the same organ.

Radiopharmaceuticals are to be given only by or under the direct supervision of a doctor with specialized training in nuclear medicine.

OncoScint(R) CR/CV (satumomab pendetide) was discontinued in the United States on December 26, 2002.

Marketing of NeutroSpec (technetium 99m TC fanolesomab) was discontinued by Palatin Technologies, their marketing partner, Mallinckrodt, and the FDA. The risk of severe and fatal allergic-type reactions outweigh its benefit.

This product is available in the following dosage forms:

Kit

Before Using

In deciding to receive a diagnostic test, the risks of taking the test must be weighed against the good it will do. This is a decision you and your doctor will make. For these tests, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

For most radiopharmaceuticals, the amount of radiation used for a diagnostic test is very low and considered safe. However, be sure you have discussed with your doctor the benefit versus the risk of exposing your child to radiation.

Geriatric

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. Although there is no specific information comparing use of most radiopharmaceuticals in the elderly with use in other age groups, problems would not be expected to occur. However, it is a good idea to check with your doctor if you notice any unusual effects after receiving a radiopharmaceutical.

Pregnancy

Radiopharmaceuticals usually are not recommended for use during pregnancy. This is to avoid exposing the fetus to radiation. Some radiopharmaceuticals may be used for diagnostic tests in pregnant women, but it is necessary to inform your doctor if you are pregnant so the doctor may reduce the radiation dose to the baby. This is especially important with radiopharmaceuticals that contain radioactive iodine, which can go to the baby's thyroid gland and, in high enough amounts, may cause thyroid damage. Be sure you have discussed this with your doctor.

Breastfeeding

Some radiopharmaceuticals pass into the breast milk and may expose the baby to radiation. If you must receive a radiopharmaceutical, it may be necessary for you to stop breast-feeding for some time after receiving it. Be sure you have discussed this with your doctor.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Proper Use

The nuclear medicine doctor may have special instructions for you in preparation for your test. For example, before some tests you must fast for several hours, or the results of the test may be affected. For other tests you should drink plenty of liquids. If you do not understand the instructions you receive or if you have not received any instructions, check with the nuclear medicine doctor in advance.

Precautions

There are usually no special precautions to observe for radiopharmaceuticals when they are used in small amounts for diagnosis.

Some radiopharmaceuticals may accumulate in your bladder. Therefore, to increase the flow of urine and lessen the amount of radiation to your bladder, your doctor may instruct you to drink plenty of liquids and urinate often after certain tests.

Make sure your doctor knows if you are planning to have any future thyroid tests. Even after several weeks, the results of the thyroid test may be affected by the iodine solution that may be given before the radiopharmaceutical.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. When radiopharmaceuticals are used in very small doses to study an organ of the body, side effects are rare and usually involve an allergic reaction. These effects may occur almost immediately or a few minutes after the radiopharmaceutical is given. It may be helpful to note the time when you first notice any side effect. Your doctor, nuclear medicine physician and/or technologist, or nurse will be prepared to give you immediate medical attention if needed.

Check with your doctor or nurse immediately if any of the following side effects occur:

Rare

Chills

difficulty breathing

drowsiness (severe)

fainting

fast heartbeat

fever

flushing or redness of skin

headache (severe)

nausea or vomiting

skin rash, hives, or itching

stomach pain

swelling of throat, hands, or feet

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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